Connoisseurus Rex
Well-Known Member
I was going to post this in the advanced section, but even new growers can do it, so what the hell.
There's a lot of talk about grow room temps. While temperature can certainly have an impact on growing, it's only a big impact if other factors are not addressed.
Plants have 3 major functions. Photosynthesis, respiration, and transpiration... None which require a specific temperature to perform, with the exception of transpiration. That being said, temperature does effect how efficiently these processes function.
Photosynthesis is dependent on water supply, light, and CO2. Respiration has the same limiting factors. Neither are temp dependent.
Now we come to transpiration. This is the more important one in my opinion. Transpiration limiting factors are RH, water supply in the medium, light, wind, and temp (to a degree based on plants life stage).
Taking all of that into account, temperature is the least significant driving force in a plants growth cycle.
While it's true that photosynthesis production can be increased with temperature, it is more reliant on the other factors. If your area is cold but you keep your canopy warmer and your soil from freezing, photosynthesis will occur at peak levels. The same rules apply to respiration.
Here is my theory on respiration and cold growing based solely on my growing experiences. Respiration is the opposite function of photosynthesis. Photosynthesis stores energy and respiration burns it off. Photosynthesis requires CO2, whereas respiration requires oxygen. The colder and denser the air, the more oxygen capacity it has. The more oxygen available to the plant, the more it can "breathe".
In a colder environment, photosynthesis can still peak with a warm canopy and above freezing soil. It also becomes an oxygen rich environment. This allows the plant to do more work, more efficiently when used in conjunction with transpiration. I'll be back to talk about that in a moment.
There's a lot of talk about grow room temps. While temperature can certainly have an impact on growing, it's only a big impact if other factors are not addressed.
Plants have 3 major functions. Photosynthesis, respiration, and transpiration... None which require a specific temperature to perform, with the exception of transpiration. That being said, temperature does effect how efficiently these processes function.
Photosynthesis is dependent on water supply, light, and CO2. Respiration has the same limiting factors. Neither are temp dependent.
Now we come to transpiration. This is the more important one in my opinion. Transpiration limiting factors are RH, water supply in the medium, light, wind, and temp (to a degree based on plants life stage).
Taking all of that into account, temperature is the least significant driving force in a plants growth cycle.
While it's true that photosynthesis production can be increased with temperature, it is more reliant on the other factors. If your area is cold but you keep your canopy warmer and your soil from freezing, photosynthesis will occur at peak levels. The same rules apply to respiration.
Here is my theory on respiration and cold growing based solely on my growing experiences. Respiration is the opposite function of photosynthesis. Photosynthesis stores energy and respiration burns it off. Photosynthesis requires CO2, whereas respiration requires oxygen. The colder and denser the air, the more oxygen capacity it has. The more oxygen available to the plant, the more it can "breathe".
In a colder environment, photosynthesis can still peak with a warm canopy and above freezing soil. It also becomes an oxygen rich environment. This allows the plant to do more work, more efficiently when used in conjunction with transpiration. I'll be back to talk about that in a moment.
